Three general areas of work are contemplated. Alpha-Fetoprotein: The role of this protein in the immune responses will be investigated with particular reference to the role of some of its unusual fatty acids. Correlating studies of rat alpha-fetoprotein obtained from animals with transplantable hepatomas, from fetal tissues and from pregnancy serum will be carried out. Immunoglobulins: Studies of the relationships of the Mcg type of gamma-chain contant region to variable region sequences will be explored. The ability of different Mcg type region. Myeloma proteins with specific antibody activity that can be crystallized will be sought and integrated in these type approaches. Metalloproteins: The role of metallothionein in copper metabolism will use human and rat liver sources. Of particular concern is the determination of whether a protein known as chelatin differs from metallothionein and the basis of the shift from a copper metallothinein in fetal life to a protein possessing mostly cadmium and zinc. The status of metallothinein in Wilson's and in Menke's disease will be emplored within the limits of available clinical material.